Dallas Semiconductor Corporation of Dallas, Tex. has created a series of electronic buttons which are marketed under the trademark "Touch Memory.TM.." These electronic buttons consist of a semiconductor chip secured within a coin-shaped stainless steel container which is approximately 16.3 millimeters in diameter and 5.8 millimeters thick, similar in appearance to a large watch battery. Just like a watch battery, these electronic buttons are circular in shape and constructed with joined circular female and male members. The female member comprises one surface of the container and its sides, while the male member is designed to be inserted into the female member to comprise the second surface of the container. The electronic button is assembled such that the female and male members are electrically insulted from one another, thus enabling the female and male members to serve as separate electrical terminals when the electronic button is in use, similar to the positive and negative terminals of a watch battery.
When the electronic button is assembled, a semiconductor chip having a ground and a signal pin is secured within the container. The semiconductor chip's ground pin is electrically connected to the female member and the semiconductor chip's signal pin is electrically connected to the male member. This allows the female member to serve as the ground terminal and the male member to serve as the signal terminal for the encased semiconductor chip.
The electronic button's internal semiconductor chip is uniquely designed such that by attaching the electronic button ground terminal to ground and simultaneously attaching the signal terminal to an appropriately activated electrical signal, the electronic button is able to deliver data stored in the semiconductor chip onto the signal line and/or receive data sent on the signal line. One of the unique features of the electronic button is that data may be delivered and/or received in a very brief period of time, thus only requiring a momentary contact with the ground and signal terminals. In one application, a "read-only" electronic button can be programmed with a unique identification number which enables the electronic button to serve as an electronic key. In another application a "read/write" electronic button may be used to record and keep track of a patient's medical data which may be placed on a bracelet and worn by the patient during the patient's hospital stay. The internal semiconductor chip may be designed with various other functionalities and used in many applications.
One of the problems encountered with the use of electronic buttons is the design of an acceptable receptacle to receive the electronic button. The receptacle, upon receipt of the button, makes the appropriate ground and signal contacts with a device to which the button interfaces, such that data and/or signals may be transferred between the interface device and the button's internal semiconductor chip. Various receptacles are available that utilize a circular electronic button retainer, hardwired to the interface device and having an outer ground contact and an inner signal contact into which the electronic button is inserted. Once inserted, the ground and signal contacts complete an electrical circuit through the electronic button to activate its internal semiconductor chip and the transfer of data to or from the interface device.
While the foregoing receptacle design is suitable for most applications, drawbacks exist when the design is employed in connection with certain types of electronic enclosures. For example, the ground and signal contacts of the receptacle, when not in operation with the electronic button, often remain exposed on the face of the enclosure thereby creating a potential for short circuit activation and/or damage to the interface device connected to the receptacle. Further, the single-piece construction of the receptacle, and the hard-wired electrical connections between the receptacle and the interface device, make it difficult to incorporate the receptacle into an electronic enclosure that has a removable cover. In particular, upon removal of the cover to which the receptacle is mounted, the electrical wiring extending between the receptacle and the interface device must be disconnected, or alternatively the wiring must be of sufficient length to avoid inadvertent disconnection.
The above problems associated with existing electronic button receptacles are of particular concern when the electronic enclosure involved is the housing of a personal computer. Generally, electronic buttons are used with personal computers as an electronic key for verifying access to the system and for other intelligent data transfer operations. The receptacle of the electronic button is typically incorporated into the front bezel, i.e, the removable cover, of the computer housing. The receptacle is then connected by wiring to interface circuitry within the computer to enable data communication between the electronic button and the computer. Since most personal computers reside on a desktop surface, there is an increased risk of conductive material, e.g., pens, paper clips and the like, accidentally short-circuiting the contacts of the receptacle and thus causing damage to the interface circuitry inside the computer. Also, removal of the computer's cover is often necessary to access memory cards, peripheral cards and other parts of the computer. The electronic receptacle is traditionally mounted on the cover and a fly-wire connects the receptacle to the interface circuitry within the computer. The fly-wire enables partial removal of the cover from the computer housing without disconnection of the receptacle. However, the fly-wire can be easily severed and tethering the receptacle to the computer in this fashion is both unwieldy and inconvenient.
Consequently, there is a need for an apparatus that protects the ground and signal contacts of an electronic button receptacle from being inadvertently short-circuited by contact with foreign objects.
There is a further need for an apparatus that permits an electronic receptacle to be mounted on a removable cover, e.g., bezel, of an electronic housing without requiring a wired electrical connection between the receptacle and interface circuitry of the housing, thereby facilitating removal and replacement of the cover relative to the housing.